hey i need to write this for anyone might get same idea i got.
bpi r3 mini is very cool and fun board to mess with as it has decent hardware, but its advertised to be capable of running 5g connection/gateway and thats where i consider it misleading information. i bought brand new rm520ngl to pair it with the board but its barely detected on openwrt/immortalwrt/bananawrt most of times modem show once and disappear forever its not powersupply not software not modem firmware or hardware, its the board capabilities
openwrt
BusyBox v1.36.1 (2025-10-19 16:37:45 UTC) built-in shell (ash)
_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
-----------------------------------------------------
OpenWrt 24.10.4, r28959-29397011cc
-----------------------------------------------------
=== WARNING! =====================================
There is no root password defined on this device!
Use the "passwd" command to set up a new password
in order to prevent unauthorized SSH logins.
--------------------------------------------------
root@OpenWrt:~# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux 6.6.110 xhci-hcd xHCI Host Controller
Bus 002 Device 001: ID 1d6b:0003 Linux 6.6.110 xhci-hcd xHCI Host Controller
root@OpenWrt:~#
immortalwrt
BusyBox v1.36.1 (2025-06-25 15:36:28 UTC) built-in shell (ash)
.___ __ .__
| | _____ _____ ____________/ |______ | |
| |/ \ / \ / _ \_ __ \ __\__ \ | |
| | Y Y \ Y Y ( <_> ) | \/| | / __ \| |__
|___|__|_| /__|_| /\____/|__| |__| (____ /____/
\/ \/ BE FREE AND UNAFRAID \/
-----------------------------------------------------
ImmortalWrt 24.10.2, r33247-467867283bb9
-----------------------------------------------------
=== WARNING! =====================================
There is no root password defined on this device!
Use the "passwd" command to set up a new password
in order to prevent unauthorized SSH logins.
--------------------------------------------------
root@ImmortalWrt:~# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux 6.6.93 xhci-hcd xHCI Host Controller
Bus 002 Device 001: ID 1d6b:0003 Linux 6.6.93 xhci-hcd xHCI Host Controller
root@ImmortalWrt:~#
bananawrt
BananaWRT login: root
BusyBox v1.36.1 (2025-10-27 14:10:17 UTC) built-in shell (ash)
=== WARNING! =====================================
There is no root password defined on this device!
Use the "passwd" command to set up a new password
in order to prevent unauthorized SSH logins.
--------------------------------------------------
____ _ ______ ______
/ __ )____ _____ ____ _____ ____ | | / / __ \/_ __/
/ __ / __ `/ __ \/ __ `/ __ \/ __ `/ | /| / / /_/ / / /
/ /_/ / /_/ / / / / /_/ / / / / /_/ /| |/ |/ / _, _/ / /
/_____/\__,_/_/ /_/\__,_/_/ /_/\__,_/ |__/|__/_/ |_| /_/
BananaWRT - Custom Firmware for Banana Pi R3 Mini v24.10.4
──────────────────────────────────────────────────────────
Hostname: BananaWRT
Uptime: 0 min
WAN IP: Not connected
root@BananaWRT:~# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux 6.6.110 xhci-hcd xHCI Host Controller
Bus 002 Device 001: ID 1d6b:0003 Linux 6.6.110 xhci-hcd xHCI Host Controller
root@BananaWRT:~#
modem side
inserted properly
QMI 
PCIE MODE IS OFF
LATEST FIRMWARE FOR THE MODEM
been like days diagnosing this but i believe i reach the point its impossible to make it work properly, if theres something i miss please do tell me TY.